Patricio Bustos, head of Chile's medical legal service said Neruda's body was in good shape after the one-hour exhumation. His remains were being taken for tests.

Neruda was also a left-wing politician and he would have been would have been an influential voice in exile against the dictatorship, but he died 12 days after the 1973 military coup at a Santiago hospital.

Dr Bustos said: "The most complex part will be searching for toxic substances that could not only be classic poisons, but also, according to testimonies, could be medical substances at very high doses to harm the poet."

Neruda, who won the Nobel prize for literature in 1971, was best known for his romantic verses, especially the collection "Twenty Love Poems and a Song of Despair." He was also a close friend of socialist president Santiago Allende, who committed suicide rather than surrender to troops during the September 11, 1973 coup led by General Augusto Pinochet.

Neruda planned to go into exile. Just a day before he was scheduled to leave, he was taken by ambulance to the Santa Maria hospital in Santiago to keep him safe from political persecution.

Officially, Neruda died there on September 23 from natural causes related to the emotional trauma of the coup. For years, his driver and bodyguard, Manuel Araya has said that the poet was murdered when agents of the dictatorship injected poison into his stomach at the clinic.

"If it hadn't been for that shot Neruda wouldn't have died," Araya said. "After seeing him being removed from the site, I felt a huge amount of pain because I lived the 24 hours with Neruda before his death. It took a long time, but justice has been served."

Former president Eduardo Frei Montalva died at the same clinic nine years later. Although doctors listed the cause of his 1982 death as septic shock from stomach hernia surgery, an investigation almost three decades later showed that the vocal opponent of the Pinochet regime had been slowly poisoned to death.